This invention relates to a device for dispensing pieces of paper of predetermined length, more particularly paper hand towels, comprising means for carrying a first roll of paper and a second replacement roll of paper, a sensor arranged to sense the web of paper from the first roll, and a device which is connected to the sensor and which, immediately after the first roll of paper has been used up, causes the paper delivery to change over to the replacement roll.
The conventional devices for dispensing pieces of paper, e.g. paper towel dispensers, have only one supply roll of paper. When this has been used up, the attendant must immediately insert a new roll to keep the dispenser in operation.
Attention is thus required at specific times which cannot be accurately predicted, for the insertion of a new roll of paper; and this is relatively uneconomic and also does not provide sufficient guarantee that paper will always be available for a user of the dispenser. This is a disadvantage of paper roll dispensers in comparison with the dispensers in which folded pieces of paper are stacked one upon the other.
To alleviate the above problems it is already known to provide a replacement paper roll in the device, such replacement roll automatically delivering pieces of paper after the first roll has been used up. In this way the interval before the device requires attention is increased while such attention can be given at specific intervals of time without the dispenser being out of operation.
Known devices of this kind have various disadvantages which inhibit reliable and economically viable use. For example, the device disclosed in U.S. Pat. No. 3,288,387 requires specially constructed cores for the paper rolls. In addition, the sensor and the device for supplying the leader of the replacement roll to the paper feed system (a gap between a feed roller and a backing roller) have a relatively complicated construction, which is therefore liable to give trouble, so that operational reliability is not adequate. In addition, the relatively complicated procedure for the replacement of the paper rolls requires trained and therefore costly staff.
In the device disclosed in U.S. Pat. No. 3,917,191, there is only relatively little space available for the first paper roll. Since, when a paper roll is replenished during servicing, the replacement roll already in use has to be moved to the position provided for the first roll, and the fresh roll has to be placed in the position provided for the replacement roll, the device can be re-filled only after some of the replacement roll has been used up. This means that the time available for refilling is reduced, with an adverse effect on the economics of the device. In addition, in this known device the supply of the replacement paper leader to the paper feed device (a gap between a feed roller and the backing roller) is again relatively complicated and liable to give trouble, so that operational reliability is not adequate.
The object of this invention is to alleviate the disadvantages of the known devices and provide a device which is of simple construction and easy to service; and in which the replacement paper roll leader can be reliably fed to the paper feed device after the first paper roll has been used up.